Dr. Jeffrey S. Gaffney obtained his undergraduate and graduate training in physical organic chemistry from the University of California at Riverside, under the guidance of Dr. James N. Pitts, Jr. He was a nationally and internationally known Senior Chemist at three of the U.S. Department of Energy (DOE) National Labs (Brookhaven, Los Alamos, and Argonne) for 31 years before coming to the University of Arkansas at Little Rock (UALR) in 2006 as Chair and Tenured Professor of Chemistry. On July 1, 2016 Dr. Gaffney retired as Emeritus Professor of Chemistry at UALR. Dr. Gaffney has published over 200 peer‐reviewed papers, 25 book chapters, and edited two American Chemical Society symposium book volumes. His research spans a wide range of chemistry in all of the basic areas, and he is internationally known for his work in air and water chemistry and global change research. Dr. Gaffney has taught undergraduate and graduate courses in general chemistry, organic chemistry, environmental chemistry, and the history of chemistry. He developed a one‐semester course for senior undergraduates and graduate chemistry students entitled “Environmental Chemistry,” that he has taught for eight years. This course combines the chemistry of the atmosphere, hydrosphere, geosphere, and biosphere – and the interactions between each of these areas – which is needed to successfully understand the chemistry of the environment as a whole system.

Dr. Nancy A. Marley obtained her B.S. in Chemistry from Jacksonville University and her Ph.D. in Analytical Chemistry and Optical Spectroscopy from Florida State University under the direction of Dr. Thomas J. Vickers. Between her B.S. degree and doctoral degree, Dr. Marley was District Chemist for the Department of Environmental Quality in Florida and also the Lead Chemist for the Childhood Lead Poisoning Program for the Florida Department of Health and Rehabilitative Services. She was a postdoctoral researcher at Los Alamos National Laboratory before joining Argonne National Laboratory, where she worked for 18 years. After retiring from Argonne National Laboratory, she joined the University of Arkansas at Little Rock as an Associate Research Professor. Currently a retired scientist/scholar, she has published over 140 peer‐reviewed papers, 14 book chapters, and edited two American Chemical Society symposium book volumes. Her research has focused on the applications of laser Raman, infrared, and UV–visible–near IR spectroscopy to problems in environmental chemistry and geochemistry. She has also developed a number of analytical methods using chemiluminescent reactions and fast gas chromatography in collaboration with Dr. Gaffney.

Both Dr. Gaffney and Dr. Marley worked closely as co‐principal investigators with the geochemistry/environmental chemistry/atmospheric science staff at both Los Alamos National Laboratory and Argonne National Laboratory. They also collaborated with geoscientists at the University of Chicago and the University of Illinois at Chicago on projects ranging from atmospheric chemistry to climate change, aqueous transport of radionuclides, and instrument development.

Chemistry of Environmental Systems is written with the overall concept of teaching the subject in a manner that develops a proactive science, learning from our past experiences and using the knowledge obtained from these experiences to prevent future environmental impacts. This is differentiated from the reactive science that environmental chemistry has been in the past. Thus, environmental chemistry as a subject is not simply the measurement of pollution species in the various environmental phases, but is the understanding of the chemical processes in the natural environment and how these natural chemical processes react when perturbed by either acute or chronic additions of chemical compounds into the whole Earth system.

This book addresses the development of the chemistry of environmental systems as it has changed over the past 50 years. Chemistry of Environmental Systems evolved from a senior‐level undergraduate/lower‐level graduate course in Environmental Chemistry taught by one of the authors (JSG) at the University of Arkansas at Little Rock. This course used two textbooks as resources: Chemistry of the Upper and Lower Atmosphere, by Dr. Barbara Finlayson‐Pitts and Dr. James N. Pitts, Jr. and the Second Edition of Chemistry of the Environment, by Dr. Ronald A. Bailey, Dr. Herbert M. Clark, Dr. James P. Ferris, Dr. Sonja Krause, and Dr. Robert L. Strong. Both of these texts have influenced the writing of this book and while Chemistry of the Upper and Lower Atmosphere details atmospheric chemistry as it was known at the date of publication (2000), Chemistry of the Environment covers the subject with a more holistic approach, including the environmental problems of the atmosphere, hydrosphere, and geosphere that were clearly identified by the year of publication (2002). While teaching the Environmental Chemistry course, it became increasingly apparent that the impacts of pollution on the chemistry of the environment are global in nature, even though they were originally thought to be local issues. Also, environmental chemical reactions are not restricted to one specific environmental phase. For example, the fundamental reaction mechanisms that are important in gas‐phase chemistry of the troposphere and stratosphere are, in many cases, also important mechanisms for aqueous and surface phase reactions.

Major environmental problems, such as urban air pollution, stratospheric ozone depletion, acid rain, and catastrophic releases of pollutants like oil spills, have been well known for decades, if not centuries. The potential impacts of climate change have now brought even more attention to the fact that these environmental problems are not standalone one‐time events, but will continue to be major issues as we move forward in the Anthropocene. The impacts of the ever‐growing human population on the environment are real and require that we address these issues in a more fundamental way, focusing on the principles of environmental chemistry. This approach is very important in training future scientists in all disciplines to begin to develop critical thinking skills in order to avoid future major environmental impacts and to move toward a sustainable global environment. Indeed, fully understanding environmental impacts requires that students and future environmental researchers have a solid background in all areas of chemistry and are trained to be able to ask the right questions of engineers, biologists, and ecologists, to aid in providing the answers to important questions of energy and technology development in the years to come. These scientists will also need to be able to effectively communicate their findings to public policy makers and leaders to insure that we, as a global community, make the best decisions regarding chemical and energy use to insure that our air and water quality is maintained and to prepare to adapt to the potential impacts of our changing climate and weather patterns, induced by anthropogenic emissions from an increasing world population.

This book is intended not only for use as a textbook, but also as a reference guide to provide a solid background in environmental chemistry and the basic mechanisms involved in the various phases of the environment, which are in constant equilibrium. Some key references used in this text are pre‐2000 and are typically not accessed by current scientists, who rely on the Internet as their major source of information. Following in the tradition of the influential environmental texts noted earlier, units of measurement that are still commonly used in the environmental chemistry literature are used in this text but they are defined in terms of the accepted SI units to assist the reader in connecting current and past work in environmental chemistry with the most ease. The organization of the book first addresses the chemistry and radiative balance of the atmosphere associated with climate change and air quality. It then continues into the areas of aqueous and heterogeneous chemistry. The linkages between these areas and the biosphere are stressed to indicate the important concept that environmental impacts, in many cases, can be amplified by biospheric or geospheric feedbacks. Key concepts that are fundamental to many areas of chemistry – such as the basic principles and laws of photochemistry, thermodynamics, and kinetics – are reviewed, along with principles of organic and nuclear chemistry related to energy use. Analytical methods that are commonly used in environmental chemistry for both air and water analyses are also included so that the reader will appreciate the relationship between the fundamental principles of chemistry and the methods used to perform analyses on key environmental species.

Throughout the chapters, brief histories of the subject areas are presented to give the reader a perspective of the developing awareness of some environmental problems that we have come to understand today. In many cases these problems actually arose from perceived solutions of another problem. A classic example of this is the development of chlorofluorocarbons (CFCs) as the working fluids in refrigeration by Thomas Midgley. Seen as a major safety improvement over ammonia and butane as working fluids, the potential impacts of CFCs on the protective ozone layer in the stratosphere were not considered until almost 40 years later. The recognition and evaluation of the impacts of the CFCs led to a Nobel Prize in Chemistry to Rowland, Molina, and Crutzen in 1995, as well as to a major change in the global use of chlorinated chemicals (the Montreal Protocol of 1992). These and other examples are used to emphasize a basic principle of environmental chemistry, which is the analysis of “cradle to grave” impacts of chemicals on the environment in order to develop safer chemical products and processes for tomorrow's sustainable economies.

Chemistry of Environmental Systems: Fundamental Principles and Analytical Methods

While this text is not meant to be an extensive review of the literature, it is aimed at covering the key aspects and mechanisms of the currently identified environmental issues, which can be used to address both current and future environmental problems in a routine manner. Key fundamental properties of chemical compounds, such as their solubilities and volatilities, along with basic chemical reaction mechanisms, are reviewed and stressed. It is hoped that this textbook will encourage future environmental chemists to learn from past mistakes and use our current knowledge of the fundamental chemistry and physics of molecules and atoms to minimize future environmental impacts. Indeed, future environmental chemists will need to work together with engineers and biotechnologists to develop a safe, sustainable methodology for the global community. As part of that approach, study problems are provided at the end of each chapter, with answers provided in Appendix A. These can be used as class assignments or as individual exercises to reinforce the reader's comprehension of the material.